Composite structures such as those used in the automotive, marine, and aerospace industries may be fabricated using automated composite material application machines, commonly referred to as automated fiber placement (AFP) machines. AFP machines may be used in the aircraft industry, for example, to fabricate structural shapes and skin assemblies by laying up relatively narrow strips of composite tape or “tows,” collimated into a wider band, on a manufacturing tool. The AFP machine aligns and places a plurality of tape strips, typically six or more, in continuous edge-to-edge contact forming a single conformal band which is placed on and compacted against the tool.
In order to fabricate large complex laminated assemblies, current AFP machines using fiber placement heads may have a relatively high degree of operational flexibility. For example, current placement heads may have the ability to add, drop-off, or cut any or all of the contiguous tape strips independently of all others by providing separate, independently controllable cutters for each tape strip.
While both highly flexible and efficient, current AFP machines may have limitations in terms of their productivity. For example, current AFP machines employ a single head having multiple tape supplies that lay down aligned tape courses edge-to-edge to form a single bandwidth. In those applications where head speed has been optimized, additional increases in productivity, i.e., the amount of tape laid down per unit time, may require the provision of additional tape supplies on the head in order to increase the bandwidth. Adding tape supplies not only result in a larger and more complicated head, but may limit flexibility in some applications due, for example, to difficulties in steering a larger head.
Accordingly, there is a continuing need for improved methods and apparatus that increase the laydown rate of composite tape.